Electrically operated timing device



P 1934- c. FAYER ELECTRICALLY OPERATED TIMING DEVICE 2 Shgets$heet 1 Filed April 1, 1931 n ab M R M m U R mm \T n R A MR Sept. 4, 1934.

gia m I'iil/L c. FAYER 1,972,334

ELECTRICALLY OPERATED TIMING DEVICE Filed April 1. 1931 2 Sheets-Sheet 2 AEEE INVENTOR 07/1/7155 F El? ATTORNEY Patented Sept. 4, 1934 Wappler Electric Company, Inc., a corporation 2 of New York Application April 1, 1931, Serial No. 526,960

6 Claims. (01. 250-34) UNITED STATES PATENT OFFICE .in the proper sequence.

While mytiming device is capable of a wide variety of usesit is particularly adapted for utilization with X-ray apparatus.

In apparatus of this character it is frequently desirable to make a series of radiographic exposures of some particu- 'lar portionof the human anatomy. These exposures must usually be made in rapid succession before the organ, which is being radiographed, alters its position in performingits natural function. Itis sometimes more desirable to radiograph, the organ from two or more distinct angles in order that the resulting radiographic exposures may be studied stereoscopically. .In eitherof these events it is desirable that the period of exposure of the sensitized film to the X-rays be of the proper duration and that the second exposurefollow as expeditiously as possible, and also that the film be exposed to the X-rays for the proper period of time to give a clear and distinct picture.

The desirability of having a device which is accurate anddependable for properly timing the various exposures of the films, the rapid changing -;of the exposed film out of position and the unexposedfilm into position, and the changing of the angle of the tube or film for a stereoscopic exposure, thus becomes manifested. Timing devices, as known to the prior art, have been limited in-the scope of operations which they can perform and have been as a whole inaccurate and undependable.

It-is, therefore, an object of my invention to provide a timing device which is accurate and dependable for initiating the operation of a plurality of functions in rapid succession and in the proper sequence. 7

.;Another object of my invention is the provision of a timing device for initiating the .energization :of an X-ray tube, the shifting of the sensitized .,film and the changing of the angle of the X-ray tube and film relative to each other if desired.

, vA further-object of my invention is the provision of a timing device which initiates the operation of various parts of an X-ray apparatus with great rapidity in a predetermined sequence Still further objects of my invention will become apparent to those skilled in the art by refer- :55-

ence to the accompanying drawings wherein:

Fig. 1 is a plan view of my timing device with a portion of the apparatus broken away to better illustrate the mechanism andshowing an electrical circuit with which my device may be readily utilized.

Fig. 2 is a front elevational view of my timing device on a smaller scale showing various time settings of the device;

Fig. 3 is a rear elevational view partly in section taken on the line III-III of Fig. 1;

Fig. 4 is a cross-section taken on the line IVIV of Fig. 3 showing an engaged position of a portion of the device;

Fig. 5- is a cross sectional view similar to Fig. 4 but showing the disengaged position of a portion of the device;

Fig. 6 is a cross sectional view taken on the line VIVI of Fig. 4 showing the method of locking the device in the various time setting operaed a constant speed synchronous motor 6. A pair of upstanding lugs 7 and 8 are secured to the base member and are provided with hearing portions 9 and 10. A coarsely threaded worm shaft 11 is journaled in the bearing portions of the lugs 7 and 8 and is connected to the motor 6, by means of a conventional coupling 12, and the worm shaft is provided with an unthreaded portion 13, near one extremity, of smaller diameter than the diameter of the remaining portion of the shaft. Another pair of upstanding lugs 14 and 15 are secured to the base and are provided with suitable bearing portions 16 and 17 and a shaft 18 is journaled in these bearing portions and extends slightly beyond these lugs.

A pair of brackets 19 and 20 are rigidly secured to the ends of the shaft 18 and a square shaft f 21 is rigidly secured to these bracket members 19 and 20. A member 22, provided with an arcuate face having threads of the same size and pitch as the threads of the worm shaft 11 is adapted to engage this worm shaft and move longitudinally of the worm shaft 11 upon the square shaft 21. This member 22 is provided with a laterally extending portion 23 and has secured to its upper face a small block of insulating material 24. A spring contact member 25 of substantially U-shaped configuration is secured to this insulating block and thus moves with the member 22.

A pair of bracket members 26 are secured to the base member 5 and a spring reel 27 is jourlugs, This shaft 521s likewise provided with a of rocking the shaft 18 and the brackets 19; and

20, to cause engagement of the member 22 with the worm shaft 11. i

A plate 36 of suitable insulating material, such as bakelite or a phenolic condensation product v is mounted on the top of the lugs '7 and 8 and assists in supporting a pair of panels 37 and 38,

which are also secured to the base member. A pair of lugs 39 and 40 extend upwardly fromthis plate and a shaft 42 is journaled in these lugs.

'Acontrol knob 43 is rigidly secured to one end of. the shaft, 42 which extends through the front hf-the panel 37. The otherend ofithis shaft-has rigidly secured thereto an insulating block 44 an'd secured to the vertical faces of this block 44 ,areja pair of contact members 45 and46 -These movable member 22.

' tween theiugs .39 and,40 and a spring 48 is 512- ,.-,-g:,ur'ed to the lug '39, and arranged :to contact a surface of this square portion 47 for maintaining \contactimembers are notched; forming contact surfaces of varying lengthand when the shaft 421s. rotated by the control knob 43 these contact surfaces of varying length. are positioned to be contacted by the spring contact 25 carried by the The shaft,.42 is further provided with a square sectioni47, disposed be-' .thevcontact membersx45 and 46in their desired nnother-pair. of lugs49 and50 are secured to the plate 36 and a shaft 52 is journaled in these control knob-53 at oneof itszends and an insulatin block 54; The block 54 is provided with cont members, 55 and 56 similar to the-contact inernbers45 and .46 likewise positionedto be enggedby the spring, contact .25 carriediby the movable member 22. This shaft is also provided :Wlfih a{ square portion 5'7. and a spring 58 is arrangedto contact, the square surfaces of the porspring 48. ;v

tinn' of the shaft 57 in thesame manner as the The panels, 37 and 36 .are provided with graduqa ons indicating fractions of a-second and ro- Qt nflof. the control knobs 43 or 53 to the detudin'alli lbf the shaft 11. 1 pair .of spring contact members s ed graduation-rotates the contact members45,

positioned toa be contacted by-the member 22 and springcontact 25 duringtheiri movement ,longi varesecured to a 1ug 62, secured to the plate 36,

; andare arranged'to engage the contact members I 45and 46 ,an d'tobe thus in electrical connection with thesemembers at all positions-of the latter when rotated by the control knob =43. A similar ;p ai r ,of spring contact members 53 and 64' are likewiseimounted upon the log 65, also secured tol the plate-36, and; are arrangedtoflbe in elecl; conductive communication with-the con- ;tactlmembers 66 and 67 are mounted uponthe plate 36 and positioned in the line of travel-of 6 an 55; 55 respectively andthus varies the length of the contact surfaces'of these members 59 and bers 55, 56 and 68, 69.

The period of time in which connection will be established between the contact members 45, 46 and 55, 56 respectively will depend upon the length of the surface of these respective contact members which are engaged by the contact member 25,

carried by the member 22. The length of the engaged surfaceof the members becomes less with each graduation as marked on the panels 37 and 38, thus varying the time that the contact member 25 is in engagement with these members.

Upon energization of the solenoid 30 the plunger 32 is drawn upwardly thus moving the arm 34 and slightly rotating the shaft 18, to which it is secured, 'in the bearing portions 16 and 17. -'-Ihe brackets 19 and '20 being secured to the shaft 18 are likewise moved and cause movement-of the square shaft-'21 thus engaging-the member 22 with the worm shaft 11'. Rotation of the worm shaft 11 will thus cause longitudinal movement 'of the member 22 due to the-threaded engagement and the contact member'25 carried bythis memher will contact the various contact members during its movement :in the aforementioned manner with the member'22 has traveled its full length,

at which time, it willhave passed beyond the threaded portion to the portion13of: smaller di-' ameter. The member 22 will remain adjacent prevent the spring reel27' from-becoming'effective to retract the-member 22. Upon de r-energization of the solenoid 30 the member 22 will, how evenimmediately be retracted to the other-ex e tremity of the square shaft 21 or its starting posi- 'tion by the spring reel 27 and thechain or cable=28. The member 22 in its movement thus establishes contact between a plurality of contact members which maybe utilized to operate any desired apparatus.

As an illustration of a type of apparatus with which my timing device may be readily utilized I have shown in Figure 1 an X-rayapparatus in, which it is desirable to perform a pluralityof functions with great rapidity and intheir proper sequence.-. I have shown a pair of conductors "L1 and L2 which represent a suitable source of .commercial alternating current potential.

'A pair of conductors 100 and-102 extendlfrom this source to a junction 103 and 104 respectively. Conductors 105and 106' extend from these'junctions to the motor Band conductor 107,-extends from the junction 103, to a junction 108',-- thence,

to a junction loaand from the latter tooneend of the. winding ofthe solenoid 30.

v1 A conductor 111 v extends from the junction 104 V to a switch S1 andvfrom this: switch 'a conductor 112 extends to the other end of the-winding-of the solenoid 30; A" switch S2 is interposedbetween the conductor. '100 and the supply conductor L1 for the purpose of energizing the motor-6 and placing the timing'deviceposition for operation. The switch S1 completes the circuit to the members 55.and 56.v Another pair ofc'onsolenoid for the purpose of causing engagement of the member 22 with the worm shaft 11 as aforegagement with the contact member 45 and a conductor 114 extends from the junction 109 to the contact member 66. A conductor 115 extends from the contact member 60, which is in engagement with the contact member 46, to a junction 116 and from this latter junction a conductor extends through the coil of a relay R1 to the conductor 102, which is connected to the supply conductor L2.

Another conductor 117 extends from the junction 116 to one end of the winding of a relay B2. A conductor 118 extends directly from contact member 67 to one end of a winding of a relay R3. A conductor 119 is connected to the supply conductor L2 and extends to one end of the primary winding of a high tension transformer T1, thence to one end of the primary winding of a lowtension transformer T2 and from this point to the other end of relays R2 and R3. A conductor 120 is connected to conductor 100 and extends to a junction 122, from this junction a conductor 123 extends to a contact terminal of an oil immersed switch 121 which is actuated by the relay B1.

A conductor 124 also extends from the junction 122 to a switch S3 and from this switch to a variable resistance R. A conductor interconnects the variable resistance and the other end of the primary winding of the low-tension transformer T2. Closure of the switch S3, after closing of switch S2, thus energizes the primary winding of the low tension transformer T2. A conductor 125 extends from the remaining end of the primary winding of the high tension transformer T1 to the other contactor of the oil immersed switch 121. The secondary winding of high-tension transformer T1 supplies high potential current to an X-ray tube 126 while the secondary winding of 10W-tensi0n transformer T2, supplies heating current for the filament of the X-ray tube in the usual manner.

The solenoid 127 is connected across the conductors 118 and 119 and is thus electrically in shunt relation with the relay R3 to cause the shifting of the X-ray tube 126 simultaneously withv the movement of one of the films out of position and the other of the films into position for a radiographic exposure. The shifting of the X-ray tube changes the relative angle between the tube and film a distance corresponding to the average interpupillary distance in order that the resulting pictures may be taken from-two distinct angles for the purposes of stereoscopic study. This being a well known expedient in the art with various types of mechanism being employed for accomplishing the shifting of the tube it is believed to be unnecessary to describe in detail any specific mechanism. I have accordingly shown the plunger of solenoid 127 loosely connected to one end of a pivoted arm 127 with the other end of this arm slidably engaging a suitable ring .or collar which surrounds the X-ray tube. Movement of the plunger of solenoid 127 will, therefore, cause a corresponding shifting of the X-ray tube 126.

The spring contact members 63 and 64, which are electrically connected to the contact members 55 and 56, are connected with a pair of conductors 128 and 129 which may extend to the junction 108 and to the conductor 115, as shown in dotted lines, for again actuating the relay R1 of the oil immersed switch and the relay R2, if desired, or these conductors may be connected to other apparatus for performing any other desired functions in a like manner. A pair of-conductors 132 and 133 are connected to the contact members 68 and 69 and may likewise extend to other apparatus.

The operation of my timing device may be best understood by assuming a given problem. Assuming it is desired to utilize my timing device with X-ray apparatus in which a plurality of radiographic exposures are desired, with one exposure following the other with great rapidity, or a plurality of radiographic exposures are desired in which the relative angle between the X-ray tube and the sensitized film is to be changed with each exposure in order to permit the resulting pictures to be viewed stereoscopically, the operation of my apparatus may be described as follows:

The switch S2 is fir t closed allowing the elec trical energy to flow from the source of supply L1 and L2 by means of the conductors 100 and 102 to the motor 6. The motor will then rotate the worm shaft 11 in the direction indicated by the arrow in Figure 1. The control knobs 43 and 53 may then be set to the graduation desired and as indicated, for the period of time desired, on the panels 3? and 38. The switch S3 is next closed to energize the low-tension heating transformer T2 to heat the cathode of the X-ray tube 126 and;

the variable resistance R adjusted for the desired amount of current.

This circuit may be traced from the conductor 100 through conductor 120, junction 122, then by means of conductor 124, switch S3, variable resistance R, the primary winding of transformer T2, and thence by means of conductor 119 to the supply conductor L2. The secondary winding of the transformer T2 is thus energized and the cathode of the X-ray tube heated to a thermionic electron emitting temperature.

The switch S1 is then closed thus energizing the winding of the solenoid 30. A circuit is then completed to the motor and the solenoid 30 which may be traced from the source L1 through switch S2, conductor 100, to junction 103, from junction 103 to the motor, thence by means of conductor 105, junction 104, and conductor 102, back to supply conductor L2. A circuit to the relay may be traced from the junction 1 3, by means of a con-- ductor 107, through junction 108 and 109, to the winding of relay 30, thence by means of conductor 112, switch S1, and conductor 111 to the junction 104. Energization of the solenoid 30 raises the plunger 32 and rotates the shaft 18 allowing the member 22 to engage the threaded portion of the worm shaft 11. As the worm shaft 11 is now being rotated by the motor the engagement of the member 22 and the worm 11 causes the member 22 to travel longitudinally of the square shaft 21.

The spring contact member 25 which is of substantially U shaped configuration and is secured to the member 22 first engages the contact members 45 and 46 in its movement longitudinally of the shaft 21. This bridges the contact members 45 and 46 and completes a circuit to the coil of relay R1 of the oil immersed switch and to the coil of relay R2, which is herein shown as being employed as a relay for pressing the film against the cassette tray.

A circuit may be traced from the junction 108, which is new supplied with energy, through the conductor 113, spring contact member 59, contact member 45, through the U-shaped contact member 25 to the contact member 46, thence through spring contact member 60, conductor 115 to junction 116, and then through the winding of relay R1 to conductor 102 which is supplied with current from the source L2. The oil immersed switch then closes its contact members and completes.

-- The-period of time of the energization of the 'X-ray tube will depend upon the length of the surface of the contact members 45 and 46 which "known methods employed in the art.

the circuit to the primary winding of high tension transformer T1 which in turn energizes thesecondary winding and the X-ray tube 126.

This lattercircuit may be traced from the conductor 100 by means of conductor 120 to the junction 122, through conductor 123, through the oil immersed switch and conductor 125, through the primary winding of high tension-transformer T1 "to the conductor 119 and thence to the supply conductor L2.

"At the same time that the relay R1 is energized the relay R2 is likewise energized. This circuit "may be traced from the junction 116, which is now carrying electrical energy, through conductor 117, the'winding of relay R2 to the conductor 119 and back to the supply conductor L2 as just described. The closing of the oil immersed switch -energizes the X-ray tube and the first exposure of the object of the X-radiation is thus registered upon the first film.

were preset to give the period desired, and which are engaged for this predetermined period by the contact 25 carried by the member 22.

Further longitudinal movement of the member 22 causes the contact member 25 carried thereby to break the connection between the members and 46, and upon further movement to establish connection between the contact members 66 and 67. The bridging of these contact members 66' and 67 completes a circuit to the relay R3 which is here shown for the purpose of shifting the exposed film out of position and the unexposed film into position.

The relay or solenoid 127 is energized simultaneously with the relay R3 for the purpose of shifting the X-ray tube to alter the relative angle between the tube and films to correspond to the usual interpupillary distance by any of the Well- In the drawings I have shown the plunger of solenoid 127 as moving downwardly (Fig. 2) in response to "energization of its winding with attendant upward movement of the X-ray tube 126. Upon de-energization cf the solenoid 127 the weight of X-ray tube 126 and its associated parts causes the,

plunger to be returned to its normal or upward position. Although I'have shown the tube as being shiftable to change the relative angie'between the tube and films it is to be understood that the film holder or cassette may be tilted in lieu of the tube to change the angle.

This circuit extends from the junction 109, which is new energized, through conductor 11 1, contact member 66, through contact member 25 carried by the member 22 to contact member 67,

' the'nby means of conductor 118 to the winding of relay R3, and thence by means of conductor 119 to supply conductor L2. This trips themechanism and allows the exposed film to move out of position and the unexposed film to move into po- 2 sition at the same time the solenoid 127' is energized, as it is connected across the conductors 118 and 11 9 which are now energized.

, This relay is utilized to cause movement of the X -ray tube or shifting of the film toenable a picture of the object to be taken from a different 1 angle, as hereinbefore explained. Further movement of the member 22 longitudinally of the shaft 21 will disengage the contact members 66 and 67 and thus de-energize the relays R3 and solenoid 127, and then to establish connection between the shown in dotted lines.

- and the chain or cable 28.

contact members 55 and 56 to again energize the X-ray tube in the manner as just described.

- Shouldthesecontact members be employed for this purpose the spring contact members 63 and 64 would be connected by means of conductors 128- and 129 to the conductor 115 and junction 108 'as They may, however, be

connected to other portions of the apparatus in which it is desiredto perform other operations.

Upon further-movement-of the member 22 the" contact member 25 will disengage the contact members 55 and 56 and nextestablish connection with the contact members 68 and 69 and thus enable the circuit for the actuating of the apparatus by means of conductors 132 and 133, if desired, in thesame maner as the bridging of the contact members 66 and 67 as previously described. V

The member 22 in travel further on the shaft 21 will then disengage the contact members 68 and 69 and'move along the shafts 11 and 21' untilthe member 22 has reached its limitof travel. When the member has reached its limit of travel it will be adjacent the unthreaded portion 13 of the worm shaft which is of smaller diameter and thus no longer engages the arcuate threaded portion of the member 22. This member will, therefore, remain in this position until the switch S1 or S2 is open to de-energize the solenoid 30.

Upon de-energization of the solenoid 30 the 4 member-22 will be retracted to the other end' of the square shaft 21 by means of the spring reel 27 A suitable bumper, "of felt or rubber, 128' may be provided for absorbing the shock attendant the retraction of this memher. A similar bumper 129' may be provided.

beneath the plunger 32 of the solenoid 30 to likewise absorb the shockof this weightedmember upon de-energization of the solenoid. I a 'I The contact members 45, 46 and 55, 56 which have surfaces that vary in length corresponding may be readily adjusted as desired to give varying periods of operation. It is to be understood that although I have shown a substantially square shaft allowing only four graduations of time,

- ranging from approximately one-twentieth to onefifth of a second, my timing device may be just as readily employed to give Various other graduations by employing a hexagonal or an octagonal section in the respective shafts 42 and 52 and'by providing additional sections on the contact members 45, 46jand 55;, 56 respectively.

Although I have shown and described a specific embodiment --of my invention 1 do not desire to be limited thereon as various other modifications. of the same maybe made without departing from the spirit and scope of the invention as set forth in the followingclaims.

What is claimed is: 1. In an X-ray system, the combination with an X-ray tube anda plurality of sensitized films, of atiming device for'causing a plurality of operations in a predetermined sequence comprising an electric -motor, mechanism operated by said motor a plurality of contact members'dispose'd ad- 7 7 Furthermore the periods of operationof a portion of the apparatus jacent said mechanism, a plurality of circuits each including some of said contact members, a movable member operable by said mechanism ior engaging each of said contact members in iwuccession and for a predetermined time during its movement to complete 'each of said circuits and cause energization of said X-ray tube, the changing of the angle of said X-ray tube relative to said sensitized films and the simultaneous shiftlfi fing of one of said films out of position and another of said films into position for a radiograpnic exposure, and the reenergization of said X-ray tube, respectively in sequence, adjustable means carried by said mechanism for varying the eriod of time said movable member engages some oi'said contact members to cause a correvariation in the time period of energiza tion' ofsaid X-ray tube, and means responsive to actuation by an operator for initiating the 20.=1operation of said movable member.

2; In an X-ray system, the combination with an X-ray tube and a plurality of sensitized films, oi'atiming device for causing a plurality of operations in a predetermined sequence comprisan electric motor, mechanism operable by said motor, a plurality of contact members disposed adjacent said mechanism, a partially completed electrical circuit including some of said contact members for causing energization of said 39?.X-1ay tube from a suitable source of electrical energy, a second partially completed electrical circuit including some of said contact members in addition to those included in said first mentioned circuit, a suitable source of energy, and

lr'neans energizable by the latter for changing the angle or said X-ray tube relative to said sensitized films and for simultaneously shifting one of said films out of position and another one of said films into position for a radiographic exipiosure; a movable member included in said mechanism and operable to engage each of said contact members during its movement to complete and interrupt said first mentioned circuit, said second mentioned circuit, and again comi--'p'lete and interrupt said first mentioned circuit in succession, means carried by said mechanism for adjusting said contact members included in said first mentioned circuit for varying the period of energization of said X-ray tube, and means re- .lsponsive to actuation by an operator for initiat ing the operation of said movable member by said elect 'ic motor and mechanism.

3. In an X-ray system, the combination with an X-ray tube and a plurality of sensitized films .liof a timing device comprising a motor energiza ble from a suitable source of electrical energy, mechanism operable by said motor for completing a circuit from a suitable source of energy to X-ray tube for a predetermined period of -time, means operable by said mechanism for causing the changing of the relative angle between said X-ray tube and said film and for simultaneously causing one of said films to be moved out of position and another of said films into position for a radiographic exposure, means operable by said mechanism to again energize said X-ray tube following the changing of the angle of said X-ray tube and the shifting of said I I lms to expose another of said filmsto said X-ray W tube, and means associated with sald mechanism and electrically responsive to actuation by an operator for initiating operation of said mechanism.

4. In an X-ray system, the combination with an X-ray tube and a plurality of sensitized films,

of a timing device comprising a motor energizable from a suitable source of electrical energy, mechanism operable by said motor, a plurality of contact members disposed adjacent said mechanism, means electrically connected to some of said contact members and operable to energize said X-ray tube, means electrically connected to other of said contact members and operable to cause the changing of the relative angle between said X-ray tube and said films and for simultaneously shifting one of said films out of position and another of said films into position for a radiographic exposure, a movable member included in said mechanism and operable to establish a connection with all of said contact members in succession during its movement, to cause the operation of said first mentioned means for a predetermined period of time, operation of said second mentioned means, and again cause operation of said first mentioned means for a predetermined period of time, in sequence; and means responsive to actuation by an operator for initiating the movement of said movable memher, and said movable member being retractable to its initial position upon said last mentioned means being rendered inoperative by the operator.

5. In an X-ray system, the combination with an X-ray tube and a plurality of sensitized films,

of a timing device for causing a plurality o.

operations for a predetermined period of time and in a predetermined sequence comprising an electric motor energizable from a suitable source of electrical energy, a worm shaft driven by said motor, a plurality of contact members disposed adjacent said shaft, a partially completed circuit including some of said contact members and adapted upon completion thereof to initially energize said X-ray tube, a second partially completed circuit including other of said contae members and adapted upon completion thereof to cause the changing of the relative angle between said X-ray tube and said films following initial energization and deenergization of said X-ray tube, a third partially completed circuh 120.

including the same contact members as said second mentioned circuit and adapted upon completion thereof to cause the shifting of one of said films out of position and the other of said films into position for a radiographic exposur: simultaneously with the changing of the angle between said X-ray tube and said films, a fourth partially completed circuit including still other of said contact members and adapted upon completion thereof to again energize said X-ray tubr subsequent to the shifting of said films and the changing of the relative angle between said X-ray tube and said films, a shaft carried by a pair of rockable brackets disposed adjacent said worm shaft, a movable member carried by said shaft operable to establish a connection with the contact members of each respective circuit in succession to complete each of said circuits and cause the operation thereof in their respective sequence during its movement, said movable member being provided with a threaded portion corresponding to said worm shaft and arranged to engage the latter and to be driven thereby longitudinally of said second mentioned shaft, and a solenoid responsive to actuation by an operator for rocking the brackets supporting said second mentioned shaft to cause said movable member to engage said worm shaft.

6. In an X-ray system, the combination with an X-ray tube and a plurality of sensitized films,

of a timing device for causing a plurality of 1 operations for a predetermined period of time and in a predetermined sequence comprising an electric motor energizablefrom a suitable source of electrical energy,-a worm shaft driven by said motor, aplurality of contact members disposed adjacent said shaft with a portion thereof havingtcontact surfaces of varying length and a control knob for presetting said contact mem- ,bers to the desired contact surface corresponding to a predetermined time period, a partially completed circuit including some of said contact members having surfaces of varying length and adapted to be initially completed to cause the .energization of said X-ray tube, a second partially completed circuit including other of said contact members and adapted to be completed following initial energization and deenergization of said X-ray tube to cause the changing of the relative angle between said X-ray tube and said films, a third partially completed circuit including the same contact members as said second mentioned circuit and adapted upon completion thereof to cause the shifting of one of said films out of position and the other of said filmsinto position for a radiographic exposure simultaneously with the changing of the angle between said X-ray tube and said'films, a fourth.

partially completed circuit including other of said contact members having surfaces of varying length and adapted to be completed subsequent to the shifting 0f;said films and thechangingof theangle between said X-ray tube and saidfilms to again energize said X-ray tube, a shaft,

vto cause engagement of said movable member with said worm shaft, and said movable member being automatically retractable to its initial position in response to the deenergization of said solenoid by the operator.

' 1 7 CHARLES FAYER. 

